Experimental Determination of the Thermal Conductivity of Porous Copper

Citation

Pinkerton, Charles C. (1949) Experimental Determination of the Thermal Conductivity of Porous Copper. Engineer's thesis, California Institute of Technology. doi:10.7907/T9JD-BK76. https://resolver.caltech.edu/CaltechETD:etd-01282009-130000

Abstract

The techniques of powder metallurgy have produced porous variations of the metals copper, steel and nickel. The proposed application of these porous metals in the sweat-cooling of jet propulsion engines demands an exact knowledge of their thermal as well as their physical properties. This thesis presents an experimental determination of the thermal conductivity of copper as a function of porosity, and an insight into the way this conductivity depends on temperature. The experiments were performed on a simplified version of the apparatus used by the Bureau of Standards for solid metals. Four copper specimens varying in porosity from 22 to 42 per cent were measured. The results obtained are consistent with those predicted by other investigators from entirely different considerations. The results are summarized in two graphs. The first shows temperature versus thermal conductivity. The second gives thermal conductivity versus porosity. It is shown that porosity largely determines thermal conductivity while temperature is distinctly a second-order influence. An analytical expression for the variation of thermal conductivity with porosity is introduced, and general agreement with the experimental results is noted.

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